Pervious concrete is a unique class of concrete characterized by a network of interconnected pores within the concrete material. The pores within pervious concrete are typically of large size and occupy a significant volume fraction. The high porosity (or pore volume) allows pervious concrete to be used in flatwork applications so that water from precipitation and other sources can pass directly through the material, thus reducing runoff from a site and facilitating groundwater recharge. Pervious concrete is usually made using coarse aggregates (having particle size between 4.75 mm and 25 mm) with little or no fine aggregates (having particle size between 0.25 mm and 4.75 mm). The amount of porosity and pore structure play a significant role in the overall performance of this material.
Despite the benefits of using pervious concrete pavements, significant drawbacks and challenges need to be addressed. These include: limited use in high volume traffic areas; need for specialized construction practices; extended curing time; durability and weather resistance; and sensitivity to water content and control in fresh concrete.
Thus, there is an on-going need for novel pervious composite materials that match or exceed the physical and performance characteristics of conventional pervious concretes, and that can be mass-produced at lower cost with improved energy consumption and more desirable carbon footprint.